Using satellite communication for providing consumer-based interactive services (e.g. broadband Internet access for home users and small businesses over satellite) has been long ago envisaged. Millions of people, including in developed countries, may not have access to broadband Internet connectivity due to living in small communities and/or far from reach of the terrestrial infrastructure (e.g. cables or DSL). For these people, wireless connectivity, including via satellites, may be the only solution available (currently and in the near future) for obtaining broadband Internet access.
Though the need for consumer-based satellite communication networks was recognized long ago, relatively short supply of available capacity over Ku-band satellites led to realization of only few such networks. With the emergence of Ka-band satellites, capacity is no longer in short supply, thus large consumer-based satellite networks may now be realized.
In a large scale consumer-based satellite network, tens or even hundreds of thousands of users may be connected over a satellite to a single gateway (or hub), which is in turn connected via a high rate link to the Internet backbone (for example, through one or more optic fibers supporting traffic volumes measurable in Gbps (Giga-bits-per-second)). An efficient way to realize such a network may be to leverage on Ka-band very wide transponders (i.e. amplification chains between the receiving and the transmitting antennas of the satellite), each supporting hundreds of MHz of bandwidth (e.g. 200 to 600 MHz in some examples). Aggregating all the traffic transmitted from the gateway towards the user terminals over a single high rate carrier occupying an entire transponder of hundreds of MHz in bandwidth may allow maximizing the total throughput of the network (i.e. as all the transponder's available bandwidth and power may be utilized). With all traffic flowing via a single channel, the network may be also much simpler to manage as it may be always balanced through usage statistics.
However, while Ka-band satellites may include very wide transponders (each spanning hundreds of MHz), baseband equipment (e.g. modulators, demodulators, etc.), which may be used at the gateway and at the user terminals for transmitting and receiving signals via a satellite, may still be compatible with traditional narrow-band transponders. Traditionally, the capacity over Ku-band and C-band satellites is divided to multiple transponders, wherein each transponder supports one of 27, 36, 54 or 72 MHz of bandwidth. Thus, base-band equipment manufactured over the years for operating over such satellites supports transmission and reception of signals that can be fitted into these transponders. For example, many types of modulators and demodulators may support a maximal transmission rate of 30 Msps (Mega-symbols-per-second), which is the maximal transmission rate supportable by a 36 MHz transponder (considering roll-off factor of 0.2). Other types of modulators and demodulators may support transmission rates up to 45 Msps (i.e. fitting into 54 MHz transponders) or up to 60 Msps (i.e. fitting into 72 MHz transponders).
In order to realize a network supporting thousands of Mbps (Mega-bits-per-second), the network may have to be divided into multiple segments, each supporting only tens to few hundreds of Mbps of traffic to part of the user terminals population. With the network being so statically divided, some segments may be overloaded while other segments may be only partly utilized. Thus, a load balancing mechanism is required for at least allowing better usage of the network resources.